Vacuum cleaner with exhaust tube having an increasing cross-sectional area

ABSTRACT

A vacuum cleaner includes a cyclonic chamber having an inlet for introducing airflow for circulation around a central axis of the cyclonic chamber. A filter chamber is positioned downstream of the cyclonic chamber and has a wall. A filter is positioned in the filter chamber. An exhaust tube extends along the central axis into the cyclonic chamber. The exhaust tube includes an inlet portion receiving the airflow from the cyclonic chamber and an outlet portion directing the airflow toward the filter chamber and the filter. The filter is in close proximity to the outlet portion. The cross-sectional area of the outlet portion increases in the downstream direction to reduce the speed of the airflow passing into the filter chamber and to evenly distribute the airflow passing through the outlet opening across the filter.

RELATED APPLICATION

The present application claims priority to U.S. Provisional Patent Application No. 61/379,212, filed Sep. 1, 2010, the contents of which are incorporated herein by reference.

BACKGROUND

The present invention relates to dirt cups for vacuum cleaners, and more particularly to exhaust tubes for cyclonic separation chambers.

Cyclonic separation is a common method of separating dirt and debris from an airflow being sucked up or vacuumed by a vacuum cleaner. Cyclonic separation takes place within a cyclonic chamber. An air intake leading to the cyclonic chamber initiates a swirling or cyclonic airflow within the cyclonic chamber. Dirt and debris are directed in a radially outward direction thereby separating from the relatively cleaner air which is removed from the cyclonic chamber from a radially inward position. In some vacuums, the air is removed by an exhaust tube that extends downwardly from the top of the cyclonic chamber and along the central axis of the cyclonic chamber.

SUMMARY

The present invention provides, in one aspect, a vacuum cleaner including a cyclonic chamber, a filter chamber, and an exhaust tube. The cyclonic chamber includes an inlet for introducing airflow for circulation around a central axis of the cyclonic chamber. The filter chamber is positioned downstream of the cyclonic chamber and includes a wall. The filter is positioned in the filter chamber. The exhaust tube extends along the central axis into the cyclonic chamber and includes an inlet portion receiving the airflow from the cyclonic chamber and an outlet portion directing the airflow toward the filter chamber and the filter, which is in close proximity to the outlet portion. The cross-sectional area of the outlet portion increases in the downstream direction to reduce the speed of the airflow passing into the filter chamber and to evenly distribute the airflow passing through the outlet opening across the filter.

The present invention provides, in another aspect, a vacuum cleaner including a housing having a central axis and an outer wall extending from a first end to a second end. The outer wall defines an air inlet between the first end and the second end. A lid assembly is selectively, movably coupled to the first end. The housing and lid assembly at least partially define a dirt collection chamber. A shroud is disposed within the housing. The shroud and the outer wall at least partially define a first cyclonic separation region. A cyclone body is at least partially disposed within the shroud and at least partially defines a second cyclonic separation region. An exhaust tube is coupled to the second end. The exhaust tube includes an inlet portion and an outlet portion. The inlet portion extends into and receives air from the second cyclonic separation region. The inlet portion has a substantially uniform cross sectional area. The outlet portion is downstream of the inlet portion, and has an increasing cross-sectional area in the downstream direction. A cover member is coupled to the exhaust assembly downstream of the outlet portion. The cover member and exhaust assembly define filter chamber. A filter member is disposed in the filter chamber and separated from the exhaust assembly outlet portion by an air gap. The filter member receives a substantially evenly distributed airflow from the exhaust assembly outlet portion.

Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a vacuum cleaner.

FIG. 2 is an exploded view of a dirt cup assembly of the vacuum cleaner of FIG. 1.

FIG. 3 is a side view of the dirt cup assembly of FIG. 2.

FIG. 4 is a sectional view of a portion of the dirt cup assembly along line 4-4 of FIG. 1.

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

DETAILED DESCRIPTION

FIG. 1 illustrates a vacuum cleaner 10 that includes a dirt cup assembly 12 detachably secured to a body 14, a foot 16 including a suction nozzle 18, a handle 20, and a suction source 22. The suction source 22 can be a motor and fan assembly or other suitable structure for creating a vacuum. The vacuum cleaner 10 is shown as an upright cyclonic vacuum cleaner. Alternatively, the vacuum cleaner 10 can be of other types, including a canister vacuum cleaner, a central vacuum cleaner, and a hand held vacuum cleaner.

As shown in FIG. 2, the dirt cup assembly 12 includes a cylindrical container 24, a cover 26, a cover insert 28, a filter 30, an exhaust tube 32, a cyclone assembly 34, and a bottom lid 36. The container 24 includes an open top end 38, an open bottom end 40, an interior surface 42, an exterior surface 44, a tangential air inlet 46, a lever 48, and a locking lip 50 formed by a locking aperture 52 extending into the container 24. The lever 48 includes an actuator 54 and slides along a track 56 formed on the exterior surface. A spring 58 biases the lever toward the top end 38. Preferably, the container 24 is made of substantially transparent plastic. Alternatively, the container 24 can be other shapes.

The cover 26 is detachably secured to the container 24 at the top end 38. The cover 26 is secured by a twist-lock or other suitable relationship between the cover 26 and the container 24. The cover 26 includes a handle 60 and a release switch 62 with a locking protrusion 64. The release switch 62 detachably secures the dirt cup assembly 12 to the body 14. The locking protrusion 64 engages a corresponding locking lip (not shown) on the body 12 when the release switch 62 is in a locked position. In an unlocked position, the locking protrusion 64 does not engage the locking lip, thereby allowing the dirt cup assembly 12 to be detached from the body 14. The cover 26 is coupled to the cover insert 28 which includes fins 66 that project downwardly away from the cover 26 to contact the top surface of the filter 30. The cover 26 also defines an air outlet 68 that exits the cover 26 and leads to the motor and fan assembly 22.

The exhaust tube 32 is coupled to the open top end 38 of the container 24 and projects into the cyclone assembly along a central axis A of the cyclone assembly 34. The exhaust tube 32 includes an inlet portion 70 for receiving the airflow from the cyclonic chamber and an outlet portion 72 for directing the airflow toward the filter 30, which is disposed in close proximity to the outlet portion 72. The inlet portion 70 includes a flow straightener in the form of intersecting vanes that assists in reducing turbulence of the airflow passing into the exhaust tube 32. The cross-sectional area of the outlet portion increases in the downstream direction to reduce the speed of the airflow passing into the filter 30 and to evenly distribute the airflow passing through the outlet opening across the filter 30. There is no structure present between the filter 30 and the outlet portion 72, and therefore there is no structure that physically interferes with the airflow exiting the outlet portion 72 and entering the filter 30. The exhaust tube 32 defines a substantially constant diameter D1 over a portion of its length. The outlet portion 72 is defined by an arcuate wall rotated about the central axis A. The arcuate wall defines a radius R, which is at least 15% of the diameter D1. In some embodiments, the radius R is between 15% and 50% of the diameter D1, and in yet other embodiments, the radius R is between 15% and 25% of the diameter D1.

The outlet portion 72 increases from the diameter D1 to an outlet opening 74 having a diameter D2 on an upper wall 76 of the exhaust tube 32. The outlet opening diameter D2 is approximately twice the diameter D1. The exhaust tube 32 also includes an upwardly extending sidewall 78 disposed on the upper wall 76. A perimeter 80 of the filter 30 is supported by the sidewall 78 such that a gap 82 is provided between the upper wall 76 and a bottom of the filter 30. The gap 82 has a distance D3 of at least 5% of the diameter D1 and less than 5 times the diameter D1. In some embodiments, the gap distance D3 is between 5% and 50% of the diameter D1, in other embodiments, the gap distance D3 is between 5% and 25% of the diameter D1, and in yet other embodiments, the gap distance D3 is between 5% and 10% of the diameter D1.

A filter chamber 84 is positioned downstream of the cyclonic chamber and is defined by the upper wall 76 of the exhaust tube 32 (i.e., the bottom wall of the filter chamber 84), the sidewall 78 of the exhaust tube 32 (i.e., the sidewall of the filter chamber 84), and the cover insert 28 (i.e., the top wall of the filter chamber 84). As discussed above, the filter 30 is positioned in the filter chamber 84. The exhaust tube 32 including the flow straightener, the upper wall 76, and the sidewall 78 is integrally formed as a single molded component.

The lid 36 is pivotally connected to the container 24 by a hinge 86 located near the bottom end. The lid 36 pivots about the hinge 86 between a closed position (shown in FIG. 3) and a number of open positions. Alternatively, other hinge structures can be used to pivotally connect the lid 36 to the container 24.

As shown in FIGS. 2-4, the cyclone assembly 34 includes a frustoconical cyclone 88, a shroud 90, a skirt 92, and a support tube or tube 94. The shroud 90 is secured to the container 24 at or near the top end 38. The lower portion of the shroud 90 is secured to the upper portion of the tube 94. The skirt 92 extends radially outward from the upper portion of the tube 94. The shroud 90 includes a perforated section 96 located above the skirt 92. The cyclone 88 nests within the assembly of the shroud 90, the skirt 92, and the tube 94. The cyclone 88 includes an air inlet 98 and a dirt outlet 100. The tube 94 includes an interior surface 102 and an exterior surface 104. Alternatively, the cyclone assembly could include multiple cyclones arranged in series or in parallel with each other. In another alternative, the cyclone assembly could include a single cyclone surrounding an exhaust tube with an integrally formed shroud.

As shown in FIG. 3, a first dirt collection chamber is at least partially defined by the lid 36 in the closed position, the exterior surface 104 of the tube 94, and the interior surface 42 of container 24. A second dirt collection chamber is at least partially defined by the lid 36 in the closed position and the interior surface 102 of the tube 94.

As shown in FIGS. 3 and 4, the lid 36 is secured in the closed position by a latch 106. In a locked position (shown in FIG. 3), the latch 106 is engaged to prevent the lid 36 from pivoting about the hinge 86. In an unlocked position, the latch 106 is not engaged and the lid 36 is free to pivot about the hinge 86. To unlock the latch 106, the lever 48 is pushed down to a lowered position, where the actuator 54 pushes the latch 106 to move the latch 106 from the locked position to the unlocked position. The spring 58 returns the lever 48 to a raised position (shown in FIG. 3). The lid 36 is resecured in the closed position by pivoting the lid 36 about the hinge 86 until the latch 106 snaps into the locked position.

During use of the vacuum cleaner 10, the suction source 22 draws dirty air through the suction nozzle 18 to the tangential air inlet 46 in the container 24. The dirty air enters the dirt cup assembly 12 through the tangential air inlet 46 and is swirled in a cyclonic manner between the interior surface 42 of the container 24 and the cyclone assembly 34. This cyclonic action separates relatively large dirt particles from the dirty air. These relatively large dirt particles are collected in the first dirt collection chamber. The partially cleaned air flows through the perforated section 96 of the shroud 90 to the cyclone air inlet 98. The partially cleaned air is swirled in a cyclonic manner within the cyclone 88. This cyclonic action separates relatively small dirt particles from the partially cleaned air. These relatively small dirt particles exit the cyclone through the dirt outlet 100 and are collected in the second dirt collection chamber. The cleaned air passes through the exhaust tube 32, the filter 30, and the air outlet 68 to the suction source 22, and is finally exhausted from the vacuum cleaner 10.

To empty the dirt cup assembly 12, the dirt cup assembly 12 is released from the body 14 by sliding the release switch 62 from the locked position to the unlocked position. Then, the dirt cup assembly 12 is detached from the body 14. The dirt cup assembly 12 is then positioned above a trash can or other waste container and the lid 36 is opened to empty the dirt collected in the first dirt collection chamber and the second dirt collection chamber into the trash can. After the dirt cup assembly 12 is emptied, the lid 36 is returned to the closed position and the dirt cup assembly 12 is secured to the body 14.

Various features of the invention are set forth in the following claims. 

What is claimed is:
 1. A vacuum cleaner comprising: a cyclonic chamber having an inlet for introducing airflow for circulation around a central axis of the cyclonic chamber; a filter chamber positioned downstream of the cyclonic chamber and having a wall; a filter positioned in the filter chamber; and an exhaust tube extending along the central axis into the cyclonic chamber, the exhaust tube including an inlet portion receiving the airflow from the cyclonic chamber and an outlet portion directing the airflow toward the filter chamber and the filter, which is in close proximity to the outlet portion, wherein the outlet portion includes an outlet opening on the wall of the filter chamber upstream of the filter, wherein the cross-sectional area of the outlet portion increases in the downstream direction to reduce the speed of the airflow passing into the filter chamber and to evenly distribute the airflow passing through the outlet opening across the filter, and wherein the exhaust tube defines a substantially constant diameter over a portion of its length.
 2. The vacuum cleaner of claim 1, wherein a gap distance is defined between the wall and the filter, and wherein the gap distance is at least 5% of the diameter.
 3. The vacuum cleaner of claim 2, wherein the gap distance is between 5% and 50% of the diameter.
 4. The vacuum cleaner of claim 2, wherein the gap distance is between 5% and 25% of the diameter.
 5. The vacuum cleaner of claim 2, wherein the gap distance is between 5% and 10% of the diameter.
 6. The vacuum cleaner of claim 1, wherein outlet portion is defined by an arcuate wall rotated about the central axis, and wherein the arcuate wall defines a radius of at least 15% of the diameter.
 7. The vacuum cleaner of claim 6, wherein the radius is between 15% and 50% of the diameter.
 8. The vacuum cleaner of claim 6, wherein the radius is between 15% and 25% of the diameter.
 9. The vacuum cleaner of claim 1, wherein the outlet portion increases from the diameter to an outlet opening diameter on the wall, the outlet opening diameter being approximately twice the diameter.
 10. The vacuum cleaner of claim 1, wherein the wall and the exhaust tube are integrally formed as a single molded component.
 11. The vacuum cleaner of claim 1, wherein the wall is a bottom wall of the filter housing, and wherein the filter chamber includes an upwardly-directed sidewall, wherein a perimeter of the filter is supported by the sidewall above the bottom wall to provide a gap between the bottom wall and a bottom of the filter.
 12. The vacuum cleaner of claim 11, wherein the bottom wall, the sidewall, and the exhaust tube are integrally formed as a single molded component.
 13. The vacuum cleaner of claim 1, further comprising a first stage cyclonic chamber, and wherein the cyclonic chamber is a second stage cyclonic chamber downstream of the first stage cyclonic chamber.
 14. The vacuum cleaner of claim 1, further comprising a motor-driven fan configured to create the airflow, the filter being located upstream of the motor-driven fan.
 15. The vacuum cleaner of claim 1, wherein the inlet portion of the exhaust tube includes a flow straightener in the form of intersecting vanes.
 16. A vacuum cleaner, comprising: a housing having a central axis and an outer wall extending from a first end to a second end, the outer wall defining an air inlet between the first end and the second end; a lid assembly selectively, movably coupled to the first end, the housing and lid assembly at least partially defining a dirt collection chamber; a shroud disposed within the housing, the shroud and the outer wall at least partially defining a first cyclonic separation region; a cyclone body at least partially disposed within the shroud, the cyclone body at least partially defining a second cyclonic separation region; an exhaust assembly coupled to the second end, the exhaust assembly including an inlet portion extending into and receiving air from the second cyclonic separation region, the inlet portion having a substantially uniform cross sectional area, and an outlet portion downstream of the inlet portion, the outlet portion having an increasing cross-sectional area in the downstream direction; a cover member coupled to the exhaust assembly downstream of the outlet portion, the cover member and exhaust assembly defining a filter chamber; a filter member disposed in the filter chamber and separated from the exhaust assembly outlet portion by an air gap, the filter member receiving a substantially evenly distributed airflow from the exhaust assembly outlet portion.
 17. The vacuum cleaner of claim 16, wherein the exhaust assembly inlet portion includes a flow straightener in the form of intersecting vanes.
 18. The vacuum cleaner of claim 16, wherein the shroud, the cyclone body, and the exhaust assembly are substantially co-axially disposed along the central axis.
 19. The vacuum cleaner of claim 18, wherein the outlet portion is defined by an arcuate wall rotated about the central axis.
 20. The vacuum cleaner of claim 16, further comprising a motor-driven fan configured to create the airflow, the filter member being located upstream of the motor-driven fan. 